Give the conjugate bases of
(i) `H2_O` (ii) `HNO_3` (iii) `NH_4^+` (iv) `HCO_3^(-1)`

Explanation

To find the conjugate bases of the given acids or ions, we need to remember that the conjugate base is formed by removing a hydrogen ion (H⁺) from the acid or ion. Let's go through each one step by step.

### Step-by-Step Solution:

1. **Conjugate Base of H₂O:**
- Start with H₂O (water).
- Remove one H⁺ ion from H₂O.
- This results in OH⁻ (hydroxide ion).
...